The present invention relates to a method for operating a steering system of a vehicle, a steering system and a vehicle.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
It is known to mechanically decouple in a steering assembly or a steering system of a motor vehicle the steering wheel from the steerable wheels and the steering gear or the like. Such systems are known, for example, by the name “steer-by-wire”. In this case, a turn of the steering wheel is detected by a sensor, the output signal from the sensor is processed by a controller and converted into a control command or a control signal for controlling an electromechanical actuator and sent to the actuator to adjust a wheel angle. Conversely, reaction torques of the chassis also detected by sensors, converted by the controller into command signals which are then sent to an electromechanical actuator so as to provide to the driver a realistic reaction torque on the steering wheel. The ratio of the rotational position of the steering wheel and angle of the wheels can be adjusted by the controller to the driving situations, so that interferences due to uneven road surfaces, side winds etc. can be eliminated from the reaction torques.
In spite of the mechanical decoupling, the angle of the steering wheel is still related to the angle of the wheels, and vice versa. This is necessary to ensure a natural feedback of the wheel position and the wheel angle to the driver by way of the steering wheel when the vehicle is moving. In particular, when the vehicle is stopped, the view on the instrument cluster may be restricted depending on the position of the wheels. When the steering wheel is turned, some displays or lights of the instrument cluster may be covered. The driver will then be able to get a good reading of, for example, a status display screen, the total or daily mileage, indicator lamps or the tank fill level, only by turning his upper body or by manually adjusting the steering angle, which requires a large force or may even be prevented by a steering lock when the “Ignition is off” due to the absence of servo assistance. When a camera is installed in the area of the instrument cluster, e.g. for monitoring the driver, the view from the camera to the driver may be obstructed by a steering wheel. This may limit the functionality of the driver monitoring system. In particular, video-based driver detection may become inoperative due to obstructions. Furthermore, in some sports steering wheels, the bottom edge is flattened to facilitate entry and exit. However, if the flattened edge is not at the bottom during entry and exit, it cannot provide relief.
It would therefore be desirable and advantageous to obviate the aforedescribed disadvantages of the prior art at least in some aspects by preventing a line of sight between the instrument cluster and a driver from being obstructed by areas of the steering wheel when the ignition is switched off or when the vehicle is stopped. It would also be desirable and advantageous to improve the comfort during entry and exit of the vehicle when the ignition is switched off or when the vehicle is stopped.